The Billion Dollar Bust: Inside the undercover sting to catch the world’s most wanted money launderer.

“I always kind of liken him to a James Bond villain. He…was a bad dude in the money laundering business.” US DEA Agent

He’s the financial mastermind who laundered money for the world’s most dangerous terrorists and criminals. An underworld banker, washing billions of dollars of dirty money. His operations stretched across the globe, helping everyone from Mexican drug cartels to bikie gangs hide their criminal profits. He also operated right here in Australia.

“There's no doubt hundreds of millions was going from Australia through that network. And there's also no doubt that worldwide that network was also responsible for billions of dollars of money laundering.” NSW Police Officer

Wanted around the world, he evaded capture for decades until an unprecedented international police operation, initiated by Australia, set out to take him down.

“Here we are putting on the table a major threat, and a major target. Working with another international agency, then putting together a strategy and then coordinating this. Yes, it put the Agency, it put Australia on the map.” Australian law enforcement chief

With exclusive access, Four Corners takes you inside this extraordinary international covert operation.

“We were posing as drug traffickers and we had money to be laundered.” US DEA agent

Australian law enforcement officers and their international counterparts reveal how they set the nerve-wracking trap to reel the money man in.

“I was confident in the undercover, I was confident in the case agents and the group. However, there’s a level of anxiety when you’re managing it all, that it’s got to go, and there was a lot of sleepless nights over a few months.” US DEA Agent

The finale of the sting was like a scene from a Hollywood thriller.

“I can’t believe this is really happening, this is a pretty amazing moment.” US DEA Agent

The high stakes undercover law enforcement investigation shows the sheer scale of trans-national crime in an age of globalisation and how much the underworld relies on criminal financiers.

“Money laundering is the backbone of organised crime. Money laundering is designed to hide proceeds of crime, and the techniques that are used are vast.” NSW Police officer

THE BILLION DOLLAR BUST, reported by Linton Besser and presented by Sarah Ferguson, goes to air on Monday 5th February at 8.30pm.

It is replayed on Tuesday 6th February at 1.00pm and Wednesday 7th at 11.20pm. It can also be seen on ABC NEWS channel on Saturday at 8.10pm AEDT, ABC iview and at abc.net.au/4corners.